Convertible door or drawer front



Feb. 16, 1965 J. w. CLEMENTS, JR 3,159,231

CONVERTIBLE DOOR OR DRAWER FRONT Filed Dec. 16, 1950 2 Sheets-Sheet 1 n 1 Fig.2. we

INVEN TOR.

MEN

4 Horny Jouu W. CLEMENTS JR.

Feb. 16, 1965 w, c s, JR 3,169,281

CONVERTIBLE DOOR OR DRAWER FRONT Filed Dec. 16. 1960 2 SheetsSheet 2 INVENTOR. JOHN W. CLEMENTS ,JR.

MBM'

Affomcy United States Patent Ofilice sasaasi Patented Feb. 16, 1355 3,16,281 C4354 VERTIELE DOOR R DRAWER FRONT .lolin W. Clements, 312, N. 15th and F Sta, Richmond, Ind. Filed Dec. 16, 196i), Ser. No. 76,213 7 Claims. (til. 2l15) The present invention relates to a convertible door or drawer front and the primary object of the invention is to provide a construction of that character comprising a frame and a readily-removable panel to be mounted in the frame, together with novel, highly simple and readily manipulable means for securing such a panel in such a frame. As the description proceeds, it will become apparent that my inventive concept is applicable not only in cabinet construction but also in many other environments including, but not necessarily limited to, room dividers, decorator screens or panels and other furniture.

In recent years, a substantial industry has developed in modular, pro-built cabinet systems for installation primarily in the kitchens of modern homes. Individual wall cabinets and individual base cabinet and drawer assemblies are factory-produced in various shapes, sizes and decorative finishes which may be stocked by a local dealer in any community and from which selections may be made by builders or home owners for installation in various combinations. Rather recently, there has arisen a demand for variegation in the doors and drawer fronts of such installations, whereby the finish or decorative appearance of such doors and drawer fronts may differ in any one of several ways from the general finish or decorative appearance of the cabinet or base construction, or whereby there may be variation in appearance among the several doors and/or drawer fronts of a given installation; and some manufacturers, in an effort to satisfy that demand, have produced interchangeable doors and/or rawer fronts of varying appearances to permit the composition or" any one of a number of different arrangements in any given installation.

As a general rule, however, any such plan has heretofore necessitated the removal and replacement of an entire door or drawer front unit.

Obviously, according to any such plan, a dealer is required to maintain a relatively large stock of mutually interchangeable elements. It is a primary object of the present invention to provide a construction whereby the advantages of such systems may be fully attained while the cost of the inventory required to be maintained by a dealer is substantially reduced and the facility with which any desired variegation of arrangement may be attained is substantially improve A further object of the invention is to provide a construction whereby an individual householder, once having set up a selected installation, may readily revise and rearrange the decorative appearance of the installation without added cost, by very simple manipulation of reversible and/or interchangeable parts, and without the necessity for removing any cabinet door or any drawer front from its operative position.

A further object of the invention is to provide a structure of the character under consideration embodying removable panels together with novel means for securing any panel in place, with either of its opposite major faces selectively exposed, such securing means being of such character as to be manipulable without the use of special tools and without danger or marring any of the parts of the assembly with which it is associated.

A still further object of the invention is to provide, for use in such a structure, securing means of such charactor as to be effectively usable with panels of varying thickness.

till another object of the invention is to provide, in connection with such securing means, structural detail of such character as to prevent or inhibit access of moisture to locations where such moisture might be entrapped with deleterious effects.

An additional object is to provide, in an assembly of the character described, a reversible panel whose opposite major faces are of different decorative appearance, together with means for securing such panel in an open frame, with either of its major faces selectively exposed therethrough, without dismounting the door or drawer front with which the panel is associated.

Still further objects of the invention will appear as the description proceeds.

To the accomplishment of the above and related objects, my invention may be embodied in the forms illustrated in the accompanying drawings, attention being called to the fact, however, that the drawings are illustrative only, and that change may be made in the specific constructions illustrated and described, so long as the scope of the appended claims is not violated.

FlG. 1 is a fragmentary perspective view of a kitchen installation including one wall cabinet unit, a section of work counter and one base unit providing a cabinet door and a drawer;

FIG. 2 is an enlarged, rear elevation of a door frame for use in the invention;

FIG. 3 is a further enlarged fragmental, transverse section through an element of the door frame of FIG. 2, showing a fragment of a panel held in place in the frame by securing means constructed in accordance with one form of the present invention;

FIG. 4 is a similar section showing the retaining means in position to secure a thinner panel in place in the frame;

MG. 5 is a perspective view of a modified form of door with a removable panel;

FIG. 6 is a fragmental perspective of a drawer having a front constructed in accordance with the present invention;

PEG. 7 is a fragmentary perspective view, drawn to an enlarged scale, and illustrating a form of securing means designed to inhibit moisture entrapment;

FIG. 8 is an edge elevation, drawn to a further onlarged scale, of a portion of a retainer strip of the type illustrated in FIG. 7;

Fi 9 is a still further enlarged section taken substantially on the line 9- of FIG. 8;

FIG. 10 is a fragmentary perspective view showing a further form of socket means; and

FIG. 11 is an enlarged sectional view showing a retainer strip operatively associated with the form of socket means illustrated in FIG. 10.

Referring more particularly to FIG. 1, it will be seen that a sin le unit of a kitchen installation of the character here under consideration may comprise a work counter section ill, a wall cabinet having a hinged door 11, and a base unit supporting the Work counter and formed to accommodate a drawer 12 as well as a second cabinet door 13. The door if is formed to include a panel 14 and similar panels 15 and 1:) are embodied in the front of the drawer l2 and in the door 13, respectively. it will be seen that, in the illustrated installation, the decorative appearances of the panels l4, l5 and to differ from I each other.

According to the present invention, the door 11 comprises a generally rectangular frame 1'7 formed to provide a ledge or shelf 18 projecting into the opening through the frame and presenting a shoulder 19 which faces tosiori' between the major faces 7 head 25v presents a face Edwhich, when the fin 24 1s received in the slot 22, retentively bears upon the inner 7 'each of the ends of the panel.

ward the inner surface 2% of the frame. opposite major face 21 of the frame will be exposed when the door f V I Gbviously, the; shoulder 19 is preferably positioned closer to the frame is mounted and in closed condition.

face 221 than to the frame face Zl'l.

1 Socket means-2?, is formed in the inner edge of the frame f 17 in a plane substantially parallel with the plane of the shoulder 19 and with the plane of the frame face 2 5, and between said two planes; in the embodiment of the invention illustrated in F163. 1 to 6, the ledge it is perimetrally continuous and the socket means 22 may be a continuous slot; and in many environments this arrange ment is entirely satisfactory, However, while the'ledge 13 will almost invariably be tlius'perimetrally continuous,

the socket meansZZ may, if desired, consist of relatively I shorhdisconnected sections in the side and end members oftheframe. g g m The panel means 14 may be of any desired construction so long as it is proportioned and designed, to fit within,

" and substantially to fill, the opening through the frame '17-, resting upon the shoulder 19, and so long as its perirn her, neoprene or an extruded plastic of suitable characteristics; I presently believe that such an extruded plastic is the optimum material for use in my novel fastening means. The strip, in its optimum form, is formed at one ,edge as a substantially flat fin 24 proportioned and designed to'fit snugly within the soclcet means 2". At its opposite edge, saidstrip is formed as ahead 25 enlarged to, project oppositely beyondthe planes of the, opposite 27 and 29 of the fin 2d. Thus, the strip face of the panel 14.

The strip 23 maybe formed as a continuous, substantially rectangular loop so that, when it is used with a frame having a continuous perimetral slot 22, the fin 24 1 may be tucked into theslotthr'oughout its length and the head 25 will retaininglyengage the entire perimeter of i the inner face of the panel 14. Alternatively, 'a plurality of separate strips 23 may have their finsv entered in such" aslot at spaced points about the perimeter of the frame;

and suchseparate strips may be substantially coextensive with the-respective frame elements or they'rnay be much shorterthan such frame elements and} a plurality of such "short strips -may be, associatedwitheach side and end of th'eframe, or only four such strips may be arranged to engage the panel, for instance, substantially at the mid point of each of the sides and at the midpoint of As shown, the strip 23 is formed mentdll adjacent the'region of juncture between the fin 24 and the head 25, The abutment 3i) limits, the degree of projection of'the fin 24- into the socket means 22,. It will be seen that the opposite projections of the head 25 define surfaces 31 and 32 which are substantially perpendicular to the width of the fin 24 and which, when the strip 23- is installed, are substantially parallel with the V inner edge of the frame 17. Thus, because of the abutment3ll,the surface 31 is parallel to, but spaced from,

the inner edge of'the frame when thefasteningstrip 23' is fully seated, whereby a screw driver blade or'other simple prying implement may be inserted between the surface El and the frame edge to facilitate removal of thefin 2d rom the socket means 29,. I f Preferably, the panel'ld will comprise a relatively rigid, plate- 33f of plywood or composition having thin sheets 34 and :35 of wood veneer,

to'provide an abutsheet metal or a suitable q plastic firmly adherently a, pl 9 faces. The sheets 34 arid'351maybe suitably anddiiferently decorated by any one of the well known processes. Alternatively, l'rnay'use a' panel such asthat indicated at in FIG. 4 and described hereinbelow. i 1 A panelidentieal with the panel Eldm'ay, of course, be mounted l3; and, depending upon the wishes of the housewife, either the sheet 341 or the sheet 35 may be exposed through the opening in the door 13. Alternatively, and as suggested in FiGp l, a different kind of panel 16 may be mounted in the door 13. It will be seen that tlie'panel but it will also be 1s: is much thinnerthan the panel 14;

seen that the shape of the head is suchthat its surface 28 opposite the surfacefild projeetsfarther from the E. 2; than the surface it: projects beyond the plane 2?.

the 11124.1 'As illustrated, the panel 16 may be a single surfaces.

The drawer l2 is'provided' with a' drawer front frame 36 analogous in construction to the frame 17 and defining I an opening through which either major face of the panel 15 may be ex osed. The frame 36 is provided'with socket means 22 analogous to the so hot means 22 and fastening means is provided to secure the panelllS, in either as elected relationshi in place in the frame 36 to fill the 7 opening thcrethnough.

A different form of frame means, having some of the advantages ofthe structure hereinbefore described, and in which a reversible or interchangeable decorative panel may be mount d is illustrated inFlG. 5. Such a frame, indicated generally by t e reference numeral dllg'comprises allochiral side vrails' il and 42 joined by end rails '43 and 44. facing grooves or slots 45 and 4-6 and the end rail 43 is formed with a groove or socket 4-7 communicating at its opposite ends with the grooves 45 and 46.7 The end rail has a thiekness only equal. to the spacing of the grooves dand 47 from the front or exposed surface of the frame. i I

Thus, a paneldtl, which may preferably 'be of the Ch el1'aC1l6I,Off the panel 14, may be readily ,rernovably V mounted in the slots 45,14 6 and 47 by entering one end of the panel over the end rail 44 and sliding it into seated position in the socket 47. A bar 49 is proportioned and designed to fit upon the end rail 44 and at one edge is formed with a flange 5i) which, when the bar is seatedin position, overlaps the rear end of the panel 43. Thus, when the bar 49 is secured in place as, for instance, by means of screws 51, the panel 48 will be securely held in the frame 4%. To reverse the panel 43, or to replace it cwith an otherwise-decorated alternative panel, it is only necessary to'remove the two screws 51 thus releasing the bar 49 from the frame, after whichthepanel may he slid freely'out'of the frame'and may be replaced, either after. reversal or by arr-alternative panelj of the frame to be provided with' the removable bar 439,

reversal or replacement of the panel canbeaccomplished without removing the frame 40 from itsmounting, either as a'cabinet door or, as a drawer front f'l hus, if the frame 4% is a wall cabinet door, either its lower edge or its edge remote from its hinges will be provided with the removable bar 29.. If it is a base cabinet door, the bar 49 will be either at the upper edge of the door or at A its edge remote from its, hinges. lithe frame-All isfto ed to its opposite'major' in the same manner in the frame of the door As aflccnsequence, if the housewife elects to mount the. thin. panel loin the frame lithe fastening means 23 is .p yconiposition which may preferably be provided with o erent deco 'ative grain prints on its opposite major The side rails are formed with mutually It will be apparent that, by properly selecting the edge (,3 be used as a drawer front, the removable bar will preferaoly be at its upper edge.

It will be seen that the three panels 14, i and 16 may be arranged as desired to provide a uniform effect or to provide any desired arrangement of departure from uniforrnity, and that any one of those panels may easily be reversed Without the use of special tools, at the whim of the housewife. It will further be obvious that, in view of the special construction of the fastening means disclosed herein, it is Well within the skill of any housewife to rearrange the several panels herself, so that she may modify the general appearance of her kitchen as often as she may desire to do so.

It is well known, of course, that moisture, entrapped against wood surfaces, will deleteriously effect the wood; and wood is particularly vulnerable to detergent-laden kitchen water. In the forms of invention thus far described, portions of the slots 22, 22', 45, 46 and 47 may remain wholly open or may be ineffectively sealed by the fins 24 or the edges of the panel 48; and where the invention is applied to cabinet or drawers closely adjacent a kitchen sink area, and particularly therebelow, those slots, or portions thereof, may act as traps for such detergent-laden moisture, with highly detrimental results. Particularly for such locations, then, I prefer the forms of invention illustrated in FIGS 7 to 9 or in FIGS. and 11.

In FIG. 7, I have shown a frame element 61 formed to provide a supporting surface 61 similar to the surface 19 for accommodating a panel 62 which may be similar to either of the panels 14 or 16. In place of the slots 22 or 22, in this embodiment of the invention 1 provide the inner edge 53 of each frame element with a series of sockets or pockets 6 preferably equidistantly spaced along the length of the frame element and opening through the surface 63. Conveniently, the sockets as may be cylindrical bores. In this form of the invention, the retainer means may consist of a molded plastic strip 65 formed along one edge with a plurality of similarly-spaced, cylindrical projections 66 proportione and designed for snu preferably slightly-compressed, reception in the respective sockets 64. The strip as comprises, at its edge opposite the projections 66, a head 68 having surfaces 69 and 7f comparable to the head surfaces 26 and 23 of the strip 23 and differently spaced beyond the lateral boundaries of the projections 66, as is most clearly illustrated in FIG. 9. The strip surface a; performs the function of the abutment 33 of the strip 23, and the surfaces 71 and "7?. are functionally equivalent to the surfaces 31 and 32 of the strip 23.

When the strip 65 is fully seated, the projections 66 fill and seal the sockets 64 against the entry of moisture thereinto, and the surface 67 bears uniformly upon the frame surface 63.

Still another form of securing means capable of guarding against moisture entrapment in contact with the wood is illustrated in FEGS. l0 and 11. Therein, l have illus trated a frame element 88 having a supporting surface 31 against which the panel 82 is adapted to rest. The inner edge 83 of the element 89 is, in this embodiment of the i vention, formed with a plurality of pockets 84, each of which is elongated in the direction of length of the element 8%) and each of which is substantially parallel with the plane of the surface 81 and spaced therefrom by a dimension at least equal to the edge thickness of the panel 8. In each such pocket there is seated a cup 35, preferably formed of injection-molded plastic and formed to define a socket 86 which, when the cup is seated in its pocket, opens inwardly through the frame element surface 33. The cups are preferably so proportioned and designed that, when they are fully seated, their mouthbounding lips 87 will be flush with the surface 83. Preferably, each cup will be secured in place in its pocket by means of a raver of glue or other moisture-impervious adhesive $8, wholly covering the in ernal walls of the pocket 84 and the external walls of the cup seated therein. Thus, each pocket at is fully protected against the entrapment of moisture therein in contact with the wood surface.

In this form of the invention, a retainer strip 89 is formed to provide, at one edge, a fin 9% which is snugly receivable in the socket 85 of a cup @5. Obviously, each strip 89 may be of such a length as to be associable with one only of the cups 85, or it may be long enough to span two or more such cups, in which case it will be formed with separate fins Ell receivable, respectively, in separate cups Preferably, each fin 96} will wholly fill and seal the socket as of its associated cup, though such filling and sealing is not of vital importance since the cup itself is moisture-impervious, will not be damaged by moisture, and will protect the wooden surface of its associated pocket against the effect of any moisture which does enter its socket 86.

The surface 91 is functionally comparable to the abutment 3t? of the strip 2-3 and the surfaces 95 and 96 are functionally eguivalent to the surfaces 31 and 32 of the strip The head Q2 of the strip 89 is analogous to the head 25 and is provided with alternatively-usable surfaces 93 and M which are differently spaced from the adjacent planes of the major surfaces of the fin 99, in analogy to the surfaces as and 28 of the head 25 of the strip 23.

I claim as my invention:

1. In a device of the class described, a boundary frame defining an opening therethr-ough, ledge means at the inner edge region of said frame providing a supporting surface substantially parallel with, but spaced from, the plane of one major face of said frame, a panel disposed within said frame and resting on said supporting surface to close said opening, the inner edge region of said frame being formed with socket means extending substantially parallel with said supporting surface, disposed between said supporting surface and said one major face and spaced from said supporting surface by a dimension at least equal to the edge thickness of said panel, and retainer means for securing said panel in place in said frame comprising a strip formed at one edge with a fin portion snugly received in said socket means and formed at its opposite edge with a head extending laterally in opposite directions to difierent degrees beyond the lateral dimensions of said fin portion to define shoulders generally perpendicular to the width of said fin portion and facing toward said fin portion, said strip be'nig formed with an abutment having a face extending transversely relative to the lateral dimension of said fin portion and disposed between said shoulders and the distal end of said fin portion, said abutment face engaging said frame to maintain separation between said shoulders and said rame.

2. in a device of the class described, a boundary frame defining an opening therethrough, ledge means at the inner edge of said frame providing a supporting surface substantially parallel with, but spaced from, the plane of one major face of said frame, a panel disposed within said frame and resting on said supporting surface to close said opening, the inner edge of said frame being formed with slot means extending substantially parallel with said supporting surface, disposed between said supporting surface and said one major frame face and spaced from said supporting surface by a dimension at least equal to the edge thickness of said panel, and retainer means for securing said panel in place in said frame comprising a strip formed at one edge as a fin snugly received in said slot means and formed at its opposite edge with a head presenting surfaces facing toward the distal edge of said tin and extending oppositely beyond the planes of the major faces of said fin, said strip being formed with an abutment present ng a surface substantially perpendicular to said planes and disposed closer to the distal edge of said fin than either of said head surfaces and engaging the inner edge of said frame when said fin is so received and resting on said supporting surface to close said opening,=the inner edge of said frame being formed with socket means extending substantially parallel with said supporting surface and symmetrical with respect to a plane parallel with said supporting surface, said socket means being disposed between said supporting surface and said onemajor frame face and spaced from said supporting surface by a dimension at least equal to the edge thickness of said panel, and retainer means for securing said panel in place in said frame comprising a strip formed at one edge with a first portion snugly and reversibly received in said socket means and formed at its opposite edge with a head, said head presenting, when said first portion is seated in said socket means, a first surface substantially parallel with said plane and facing in one direction therefrom, and a second surface substantially parallel with said plane and facing in the opposite direction therefrom, said head surfaces being oppositely spaced laterally from said plane to different degrees for selective cooperative engagement with a panel resting on said supporting surface, said head further presenting shoulders oppositely projecting from said first portion and facing the inner edge of said frame, said strip having abutment means disposed between said shoulders and the distal edge of said first portion and engaging said frame to maintain separation between said shoulders and said frame.

arcaasr plane of one major face of said frame, a panel proportioned and designed to fit within said frame and resting porting surface, disposed between said supporting surface 4. In a device of the class described, a boundary frame defining an opening therethrough, ledge means at the inner edge of said frame providing a supporting surface substantially parallel with, but spaced from, the plane of one major face of said frame, a panel disposed within said frame resting on said supporting surface to close said opening, the inner edge of said frame being formed with a plurality of substantially cylindrical sockets uniformly spaced therealong and opening inwardly, the mouth of each such socket being spaced from said sup porting surface by a dimension at least equal to the edge thickness of said panel, and resiliently compressiblestrip means formed along one edge with a plurality of substantially cylindrical projections arranged in substantial parallelism, spaced therealong in conformity to the spacing of said sockets and snugly received in such sockets, said strip means further being formed to provide a first head surface substantially parallel with the plane common to said projections and spaced laterally in one direc tion from said common plane, and to provide a second head surface substantially parallel with said common plane and spaced laterally in the opposite direction and to a different degree from said comm-on plane, one of said head surfaces being retainingly engaged with a panel of one thickness when said projections are received in one order in said sockets, and. the other of said head surfaces being retainingly engaged with a panel of a different thickness when said projections are received in a reverse order in said sockets, said head further presenting shoulders extending oppositely from said common plane and facing the distal ends of said projections, said strip having abutment means disposed between said shoulders and said distal ends of said projections and engaging said frame to maintain separation between said shoulders and said frame.

5. In a device of the class described, a wooden boundary frame defining an opening therethrough, ledge means at the inner edge of' said frame providing a supporting surface substantially parallel with, but spaced from, the

and said one major frame face and spaced from said supporting surface by a dimension at least equal to the edge thickness of said panel, and a plurality of cups of resiliently distort-able, moisture-impervious material snugly seated in said socket means at spaced points about the inner perimeter of said frame and each presenting an open mouth inwardly toward said opening through said frame, and retainer means for securing said panel in place in said frame comprising a strip of resiliently compressible material formed at one edge as a fin snugly received in at least one of said cups through the mouth thereof substantially to fill said cup and formed at its opposite edge with a head proportioned and designed to bear firmly against that face of said panel remote from said suppor 'ing surface when said fin is so received in such a cup,

said head being formed to provide oppositely-facing, panel-engaging surfaces substantially parallel with the plane of said fin and oppositely and unequally spaced from said last-named plane, and said head further being formed toprovide shoulders extending oppositely from said last-named plane and facing the distal edge of said fin, and abutment means having a face extending transversely relative to the lateral dimension of said fin and disposed between said shoulders and said distal edge, said abutment face engaging said frame to maintain separation between said shoulders and said frame.

6. In a device of the class described, a Wooden boundary frame defining an opening thereth-rough, ledge means at the inner edge of said frame providing a supporting surface substantially parallel with, but spaced from, the plane of one major face of said frame, a panel proportioned and designed to fit within said frame and resting on said supporting surface to close said opening, the inner edge of said frame being formed with socket means comprising a plurality of pockets disposed between said.

supporting surface and said one major frame face and spaced from said supporting surface by a dimension at least equal to the edge thickness of said panel, and a cup of resiliently distortable, moisture-impervious material snugly seated in and filling each such pocket and presenting an open mouth inwardly toward said opening through said frame, and retainer means for securing said panel in place in said frame comprising a strip of resiliently compressible material. formed at one edge with projecting means arranged in a plane and snugly received in at least one of said cups through the mouth thereof substantially to fill said cup and formed at its opposite edge with a head proportioned and designed to bear firmly against that face of said panel remote from said supporting surface when said projecting means is so received in such a cup, said head being formed to provide oppositelyfacing, panel-engaging surfaces substantially parallel with the plane of said projecting means and oppositely and unequally spaced from said last-named plane, and said head further presenting shoulders extending oppositely from said projecting means and facing the distal end of said projecting means, and abutment means having a face extending transversely relative to said projecting means and facing toward the distal end thereof, said face being disposed between said shoulders and said distal end and engaging said frame to maintain separation between said shoulders and said frame.

7. The device of claim 6 in which the mouth of each cup lies in a plane fiush with the surface of the frame edge in which said cup is seated, and a layer of moistureimpervious adhesive is interposed between said cup and the internal walls of the pocket in which it is seated.

(References onfollowing page) 5 153 References Cited by the Examiner 2,342,352 2/44 Lowry V 20-564 E PATENT 2,830,684 4/58 Ban-crofit 189-78 UNITED ,STAT S S 2,934,801 5/60 Blaszkowski 2056.4 116-13310 5/15 Fl'ledel 2 945 2 9 7 0 Domen 0 55 4 2 9 6/78 1'? 1616 5 2,953,824 9/60 Mim'ck 2()56.4 3 5; g gig-22" 3,012,642 12/61 Emmerich 1 8978 yer 1,147,003 7/15 Edwards 20 56.4 FOREIGN PATENTS 1,223,609 5/17 Peters 20-S6.4 202,068 8/23 Great Britaln- 1,358,988 11/20 Rindsber-ger 2056.4 m 1,892,104 12/32 Hunter JACGB L. NACKENOFF, Przmary Exammer.

2,063,120 12/36 Plym 2056.4 WILLIAM L MUSHAKE, Examiner. 

1. IN A DEVICE OF THE CLASS DESCRIBED, A BOUNDARY FRAME DEFINING AN OPENING THERETHROUGH, LEDGE MEANS AT THE INNER EDGE REGION OF SAID FRAME PROVIDING A SUPPORTING SURFACE SUBSTANTIALLY PARALLEL WITH, BUT SPACED FROM, THE PLANE OF ONE MAJOR FACE OF SAID FRAME, A PANEL DISPOSED WITHIN SAID FRAME AND RESTING ON SAID SUPPORTING SURFACE TO CLOSE SAID OPENING, THE INNER EDGE REGION OF SAID FRAME BEING FORMED WITH SOCKET MEANS EXTENDING SUBSTANTIALLY PARALLEL WITH SAID SUPPORTING SURFACE, DISPOSED BETWEEN SAID SUPPORTING SURFACE AND SAID ONE MAJOR FACE AND SPACED FROM SAID SUPPORTING SURFACE BY A DIMENSION AT LEAST EQUAL TO THE EDGE THICKNESS OF SAID PANEL, AND RETAINER MEANS FOR SECURING SAID PANEL IN PLACE IN SAID FRAME COMPRISING A STRIP FORMED AT ONE EDGE WITH A 